Lexus NX: Intake Air Temperature Sensor 1 Circuit Range / Performance (P0111)

Lexus NX Service Manual / Engine & Hybrid System / 2ar-fxe (engine Control) / Sfi System / Intake Air Temperature Sensor 1 Circuit Range / Performance (P0111)

DESCRIPTION

Refer to DTC P0112.

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DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P0111	Intake Air Temperature Sensor 1 Circuit Range / Performance	Either of the following conditions is met (2 trip detection logic): The change in intake air temperature from the previous warm-up to the following trip is small The change in the intake air temperature after engine start is less than the threshold value	Mass air flow meter sub-assembly	Comes on	DTC stored

MONITOR DESCRIPTION

The ECM performs OBD II monitoring based on the values from the intake air temperature sensor. If there is no change of the sensor value within the normal range, the ECM will not be able to perform OBD II monitoring or will misdiagnose that there is a malfunction in the sensor. The ECM detects when the intake air temperature sensor value is stuck by performing monitoring after the power switch is turned off or the engine is started (short soak or long soak).

MONITOR STRATEGY

Related DTCs	P0111: Intake air temperature sensor rationality (After engine stop) P0111: Intake air temperature sensor rationality (After cold engine start)
Required Sensors/Components (Main)	Intake air temperature sensor
Required Sensors/Components (Related)	-
Frequency of Operation	Once per driving cycle
Duration	-
MIL Operation	2 driving cycles
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

All

Monitor runs whenever the following DTCs are not stored

None

After Engine Stop

All of the following conditions are met	-
Time after engine start	10 seconds or more
Auxiliary battery voltage	10.5 V or higher
Engine coolant temperature at ECM started by internal engine off timer	-40°C (-40°F) or higher
Engine coolant temperature before engine stop	70°C (158°F) or higher
Accumulated mass air flow amount in previous driving cycle	2305 g or more
Key-off duration	30 minutes
Intake air temperature sensor circuit fail (P0112, P0113)	Not detected
Engine coolant temperature sensor circuit fail (P0115, P0117, P0118)	Not detected
Mass air flow meter circuit fail (P0102, P0103)	Not detected
Soak timer fail (P2610)	Not detected

After Cold Engine Start

All of the following conditions are met	-
Key-off duration	5 hours or more
Time after engine start	10 seconds or more
Engine coolant temperature	70°C (158°F) or higher
Accumulated mass air flow amount	2305 g or more
Either of the following conditions is met	1 or 2
1. Duration while engine load is low	120 seconds or more
2. Duration while engine load is high	10 seconds or more
Intake air temperature sensor circuit fail (P0112, P0113)	Not detected
Engine coolant temperature sensor circuit fail (P0115, P0117, P0118)	Not detected
Mass air flow meter circuit fail (P0102, P0103)	Not detected
Soak timer fail (P2610)	Not detected

TYPICAL MALFUNCTION THRESHOLDS

After Engine Stop

Intake air temperature change

Less than 1°C (1.8°F)

After Cold Engine Start

Intake air temperature change

Less than 1°C (1.8°F)

CONFIRMATION DRIVING PATTERN

Connect the Techstream to the DLC3.
Turn the power switch on (IG) and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off and wait for at least 30 seconds.
Turn the power switch on (IG) and turn the Techstream on [A].
Put the engine in inspection mode (maintenance mode).
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Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher [B].
Idle the engine for 5 minutes or more [C].
HINT:

During steps [A] through [C], if the change in the intake air temperature is less than 1°C (1.8°F), the intake air temperature sensor (mass air flow meter sub-assembly) is malfunctioning. It is not necessary to continue this procedure.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [D].
Read the pending DTCs.
HINT:
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P0111.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result shows INCOMPLETE or N/A, perform steps [E] and [F].

With the engine running, drive the vehicle at 40 km/h (25 mph) or more for a total of 5 minutes or more [E].
CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

HINT:

If the engine stops, further depress the accelerator pedal to restart the engine.
Check the DTC judgment result again [F].
HINT:

If the judgment result shows INCOMPLETE or N/A, perform steps [E] and [F] again.
If no pending DTC is output, perform a universal trip and check for permanent DTCs.
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HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P0112.

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CAUTION / NOTICE / HINT

HINT:

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1.	CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0111)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(e) Read the DTCs.

Powertrain > Engine and ECT > Trouble Codes

Result	Proceed to
DTC P0111 and other DTCs are output	A
DTC P0111 is output	B

HINT:

If any DTCs other than P0111 are output, troubleshoot those DTCs first.
Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.
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GO TO DTC CHART

REPLACE MASS AIR FLOW METER SUB-ASSEMBLY

SEE MORE:

Data List / Active Test

DATA LIST / ACTIVE TEST DATA LIST NOTICE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not. HINT: Using the Techstream to read the Data List allows the values or states of

Rear Occupant Classification Sensor LH Collision Detection (B1787)

DESCRIPTION DTC B1787 is stored when the occupant detection ECU receives a collision detection signal, which is sent by the rear occupant classification sensor LH when an accident occurs. DTC B1787 is also stored when the front seat adjuster assembly RH is subjected to a strong impact, even if an ac

Lexus NX: Intake Air Temperature Sensor 1 Circuit Range / Performance (P0111)

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Intake Air Temperature Circuit Low Input (P0112,P0113)

Engine Coolant Temperature Circuit (P0115,P0117,P0118)

Engine Coolant Temperature Circuit Range / Performance (P0116)

SEE MORE:

Data List / Active Test

Rear Occupant Classification Sensor LH Collision Detection (B1787)